A wiring substrate having a stiffener member has been known. The stiffener member is provided on the wiring substrate in order to reduce warpage of the wiring substrate, especially a careless substrate.
FIG. 1 is a cross-sectional view of a related art wiring substrate having a stiffener member. Referring to FIG. 1, a wiring substrate 100 is a so-called pin grid array wiring substrate having a careless resin substrate 110, a stiffener member 120, and lead pins 130. The stiffener member 120 may be formed of a metal member having, for example, a shape of a frame, and is attached on a peripheral part of a first primary surface 110a of the resin substrate 110 with an adhesive or the like. The lead pins 130 serve as external connection terminals, and are provided on corresponding connection pads of a second primary surface 110b of the resin substrate 110. A semiconductor chip 200 is mounted on the wiring substrate 100.
In the wiring substrate 100 so configured, warpage of the resin substrate 110 can be relatively reduced because the stiffener 120 is attached on the peripheral part of the resin substrate 110.
Next, a producing method of the wiring substrate 100 on which the semiconductor chip 200 is mounted is explained. FIGS. 2 and 3 illustrate producing processes of a related art method of producing the wiring substrate having the stiffener member. First, in a process illustrated in FIG. 2, the stiffener member 120 is attached on the peripheral part of the first primary surface 110 of the resin substrate 100 that is made in accordance with a known producing method. Next, in a process illustrated in FIG. 3, the semiconductor chip 200 is mounted by way of solder in an area surrounded by the stiffener member 120 on the first primary surface 110a of the resin substrate 110. Then, after the process illustrated in FIG. 3, the lead pins 120 are attached on the corresponding connection pads of the second primary surface 110b of the resin substrate 110, and thus the wiring substrate 100 illustrated in FIG. 1, on which the semiconductor chip 200 is mounted, is obtained.